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Half-Wave Dipole Length

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Half-Wave Dipole Length

The half-wave dipole is one of the most fundamental antenna types. This formula calculates the physical length needed for resonance at a given frequency, including a typical shortening factor for real-world construction.

L = \frac{\lambda}{2} \times k = \frac{c}{2f} \times k

Alternative Forms

Practical Formula (meters)

L_m = \frac{142.5}{f_{MHz}}

Includes 95% velocity factor for typical wire antennas

Practical Formula (inches)

L_{in} = \frac{5616}{f_{MHz}}

Length in inches for the US market

📖 Example: 2-Meter Ham Radio Dipole

Calculate dipole length for 146 MHz (2-meter amateur band)

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Half-Wave Dipole Length